YPR_ML:
Yield Per Recruit analysis to get FMSY proxy F01 paired with a mean-length estimate of current stock size
Description
A simple yield per recruit approximation to FMSY (F01) which is the position of the ascending YPR curve for which dYPR/dF = 0.1(dYPR/d0)
A mean-length estimate of recent Z is used to infer current abundance